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This study investigates the association between air-lead levels and crime rates across 2,772 U.S. counties. Data for the analysis come from the Environmental Protection Agency, the Bureau of Census, and the Federal Bureau of Investigation. Results suggest that air-lead levels have a direct effect on property and violent crime rates even after adjusting for general levels of air pollution and several structural covariates of crime. We also find that resource deprivation interacts with air-lead levels. The association between air-lead levels and crime rates-property and violent-is strongest in counties that have high levels of resource deprivation and weakest in counties that have low levels of deprivation. This interaction is consistent with arguments and evidence in the health care literature that populations most at risk of lead poisoning are least likely to get the resources required to prevent, screen, and treat the illness.  相似文献   
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The authors identified the number, type, and frequency of protective behaviors that undergraduate college students who consume alcohol use to prevent alcohol-related consequences. Their hypothesis was that students who engage in more types of protective behaviors with greater frequency would be less likely to experience alcohol-related consequences. Participants consisted of a randomly selected sample of 1,355 undergraduates aged 18 years and older at a large public university. Students completed a mailed questionnaire on alcohol and health behaviors in spring 2002. The findings (after adjustment for covariates) indicated that self-protective behaviors are inversely associated with alcohol-related problems for women but not for men. The influences of gender and racial and ethnic differences are considered in relation to prevention and intervention programs aimed at reducing alcohol-related consequences on college campuses.  相似文献   
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Genetic variability and diversity are the result of a mutation-selection balance that acts permanently within and between species. The presence of deleterious mutations is a necessary consequence of this process and thus “the price paid by a species for its capacity for further evolution” (Haldane 1937, Am Nat 71:337–349). Recent estimations of mutation rate in the human lineage has revived the debate as to whether the high number of deleterious mutations poses a severe problem for the future of mankind. Theoretical considerations allow a scenario in which the survival of the human race is maintained by truncation selection of deleterious mutations that removes as many mutations as appear anew in every generation. In this case our genetic burden is carried by those individuals that suffer a genetic death resulting from random distribution of deleterious alleles. Nevertheless, one has to ask whether the mutation rate may set absolute limits on the complexity of a species.  相似文献   
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This is an empirical study of the relationship between aesthetic evaluation, collective action, and artistic success. Documentary evidence is examined to show that the initial artistic success of Jackson Pollock, the leading painter in the early years of Abstract Expressionism, was not due to coherent aesthetic evaluation by the New York art world. Secondary sources are then reviewed and it is suggested that Pollock's rise to artistic preeminence was brought about directly by collective action in the form of a promotional campaign on the part of a small, but influential, group of actors closely associated with the artist.  相似文献   
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Though often conflated, informal physical exercise and organized athletic participation have very different implications for adolescent sexual risk outcomes. The purpose of this research is to disaggregate strenuous exercise from sports, examine how each is associated with sexual risk, and explain the observed differences using the conceptual lens of cultural resource theory. Using a nationally representative sample of over 16,000 public and private high school students, we employ logistic regression to test hypotheses about the gender-specific and race-specific effects of strenuous exercise and athletic participation on adolescent sexual risk behavior. The results show that both forms of physical activity buffer sexual risk for girls. Strenuous exercise is associated with increased odds of sexual risk for boys. Sports and race interact to influence boys' sexual risk outcomes: Athletic participation is associated with lowered odds of sexual risk for white male adolescents, but heightened odds of sexual risk for black male adolescents.  相似文献   
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Effective targeted and community HIV/STD prevention programs   总被引:1,自引:0,他引:1  
Community interventions and interventions targeting specific groups at risk of STDs/HIV have demonstrated significant impacts on sexual behavior, particularly condom use and safer sex. The scientific evidence suggests the factors that make these interventions particularly effective include the establishment of community, including business and CBO partnerships; maintainance of the intervention post-research funding; and buy-in by the community or target group. The modification of risky normative beliefs through the use of opinion leaders and role models, and through intervention delivery by peer educators, is an important facet of such interventions. Interventions delivered by health professionals, absent a community base, appear to be unsuccessful. Where cultures or subcultures are targeted, the close involvement of such groups in the design and delivery of messages is critical to their success. Diffusion of interventions through existing social networks further extends the intervention into the community and acts to reinforce and maintain changes in peer norms toward safer sexual behavior. The available data confirm that community or medical infrastructure-based interventions are effective in changing sexual behavior and can reach a wider range of the population than face-to-face programs if they incorporate peer educators as role models in modifying norms, and if diffusion of the intervention is integral to the design.  相似文献   
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